For the conventional electronic device having a protection panel as described above, there can be mentioned an electronic device in which: a recess is formed in a front casing where a display unit is mounted inside; in a bottom face of the recess, an opening for allowing a display part of the display unit to face externally is formed; and a protection panel for the display unit is fitted into the recess in such a manner that a rim portion of the protection panel is directly supported by a rim of the bottom face of the recess.
Recent mobile-phones and smartphones, as examples of the electronic device having a protection panel, are provided with e-mail function and internet function in addition to the basic telephone function, and further with camera function and music player function. In this manner, there is a tendency that multifunctionality is imparted to the electronic devices. In order to realize the multifunctionality while preventing a growth in size of the electronic device, it is necessary to reduce a number of switches to be added, by allowing the switches provided for exerting the basic function to serve for other functions.
However, when a degree of serving for other functions becomes too large, the number of roles assigned to each switch becomes too large, leading to decrease in operability. In addition, the number of switches for exerting the basic function and the number of switches to be newly added have limitation. Therefore, to further increase the number of the functionality of the electronic device requires the growth in size of the electronic device.
Accordingly, as described in Patent Document 1, it has been proposed that, by efficiently utilizing the protection panel intrinsically provided in the electronic device having protection panel, the number of the functionality of the electronic device is further increased while preventing and suppressing the growth in size and decrease in operability of the electronic device, or alternatively, the operability is enhanced while preventing and suppressing the growth in size of the electronic device.
An electronic device 10 having the protection panel disclosed in Patent Document 1 includes: a display device 3 having a single display part 3A; a housing 2 for mounting the display device 3 therein which has a display window 2A including an opening to allow the display part 3A to face externally and a supporting portion 2b in a shape of a frame; the protection panel 104 fitted into the display window 2A, whose back side rim portion 104A is supported by the supporting portion 2b; and a pressure-sensitive conductive rubber 14 which is disposed between the protection panel 104 and the supporting portion 2b and configured to detect a pressing operation on the protection panel 104 (see FIG. 18). FIG. 18 is a cross sectional view taken along a line A-A of the mobile-phone in FIG. 17.
According to the above-described configuration, a pressure sensor can be obtained in which the protection panel 104 serves as an operation part, and the pressure-sensitive conductive rubber 14 serves as a sensor element. Therefore, the pressure sensor can be used as a switch corresponding to the function newly added to the electronic device, or as a switch to which a role is assigned that is otherwise played by the existing switch.
If the pressure sensor utilizing the protection panel 104 is used as, for example, a switch corresponding to the function newly added to the electronic device, a space for arranging a special-purpose switch dedicated to a new function becomes unnecessary that is otherwise required for newly introducing the special-purpose switch, or alternatively, an assignment of the role corresponding to the new function to the existing switch, that is required for allowing the existing switch to serve as a switch for new function, can be reduced. As a result, the multifunctionality of the electronic device can be realized while preventing or suppressing the growth in size of the electronic device which may otherwise be caused by securing the space for arranging the special-purpose switch, and preventing or suppressing the decrease in operability which may otherwise be caused by allowing the existing switch to serve as a switch for new function.
In addition, if the pressure sensor utilizing the protection panel 104 is used as, for example, a switch to which a role is assigned that is otherwise played by the existing switch, the space for arranging the special-purpose switch, to which a role is assigned that is played by the existing switch, becomes unnecessary that is otherwise required for newly introducing the special-purpose switch. As a result, operability can be enhanced while preventing and suppressing the growth in size of the electronic device that would otherwise occur by securing the space for arranging the switch.    Patent Document 1: WO2007/091600